S.J.
My son used his binky until he was 26 months. I was more concerned about finding a time when not too much was going on in his life so we could concentrate on the binky. So I waited until I was done with my pregnancy, and he was used to the new baby. Once all was settled, I worked on his binky.
He used it only for naptime and bedtime. So I started with naptime. I just didn't give it to him. It only took one weekend to get him over it. I've been sending him to daycare since he was 14 months and he never needed a binky for naptime there, so he should need one for naptime at home. After 2 weekends more of no binky at naptime, I started bedtime. Amazingly enough, it only took 2 nights. On the third night, he didn't ask for it at all. The first night took about 45 minutes to get him to go to sleep though. The second night took about 20 minutes (15 minutes is the norm, so that wasn't bad at all). About 4 or 5 nights after he did ask for one and I just told him that he didn't need one anymore and he just said "okay" and that was it.